Comparative study of self-assembling of multilayers using reactive sputter deposition and mass selective ion beam deposition

While experimenting with the growth of metal-containing amorphous carbon (a-c:Me) thin films using two different growth processes, self-assembled multilayered structures were observed. One of the processes is a reactive magnetron sputter deposition process. The other process is a mass selective ion beam deposition process. Despite of the differences in the growth method and the growth condition, self-assembled multilayered thin films, consisting of alternating dark layer and bright layer, were obtained in both processes. Based on the consideration of energy for atomic diffusion in the thin films, the growth mechanism is discussed.     

Structural Studies of the Lipopolysaccharide of Aeromonas veronii bv. sobria Strain K133 Which Represents New Provisional Serogroup PGO1 Prevailing among Mesophilic Aeromonads on Polish Fish Farms

In the present work, we performed immunochemical studies of LPS, especially the O-specific polysaccharide (O-PS) of Aeromonas veronii bv. sobria strain K133, which was isolated from the kidney of carp (Cyprinus carpio L.) during an outbreak of motile aeromonad infection/motile aeromonad septicemia (MAI/MAS) on a Polish fish farm. The structural characterization of the O-PS, which was obtained by mild acid degradation of the LPS, was performed with chemical methods, MALDI-TOF mass spectrometry, and ¹H and ¹³C NMR spectroscopy. It was revealed that the O-PS has a unique composition of a linear tetrasaccharide repeating unit and contains a rarely occurring sugar 2,4-diamino-2,4,6-trideoxy-D-glucose (bacillosamine), which may determine the specificity of the serogroup. Western blotting and ELISA confirmed that A. veronii bv. sobria strain K133 belongs to the new serogroup PGO1, which is one of the most commonly represented immunotypes among carp and trout isolates of Aeromonas sp. in Polish aquacultures. Considering the increase in the MAI/MAS incidences and their impact on freshwater species, also with economic importance, and in the absence of an effective immunoprophylaxis, studies of the Aeromonas O-antigens are relevant in the light of epidemiological data and monitoring emergent pathogens representing unknown antigenic variants and serotypes.     

Hydrophilic polycarbonate chips for generation of oil-in-water (O/W) and water-in-oil-in-water (W/O/W) emulsions

Modification of the surfaces of polycarbonate (PC) with the use of a solution of tin (II) chloride renders them hydrophilic. The surface draping is stable against exposure to water and to alcohols. Exposure to alkanes reduces but does not diminish the effect. The method is compatible—in using the same solvent and temperature—with the hydrophobic modification of PC Jankowski et al. ( Lab Chip 11:748–752, 2011). The combination of these methods makes it possible to generate single and multiple monodisperse emulsions with the use of flow-focusing junctions in systems made in PC—material that is suitable for fabrication of multilayer, high throughput microfluidic devices.     

Functionalised Anodised Aluminium Oxide as a Biocidal Agent

In this article, we describe the antimicrobial properties of a new composite based on anodic aluminium oxide (AAO) membranes containing propyl-copper-phosphonate units arranged at a predetermined density inside the AAO channels. The samples were prepared with four concentrations of copper ions and tested as antimicrobial drug on four different strains of Escherichia coli (K12, R2, R3 and R4). For comparison, the same strains were tested with three types of antibiotics using the minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests. Moreover, DNA was isolated from the analysed bacteria which was additionally digested with formamidopyrimidine-DNA glycosylase (Fpg) protein from the group of repair glycosases. These enzymes are markers of modified oxidised bases in nucleic acids produced during oxidative stress in cells. Preliminary cellular studies, MIC and MBC tests and digestion with Fpg protein after modification of bacterial DNA suggest that these compounds may have greater potential as antibacterial agents than antibiotics such as ciprofloxacin, bleomycin and cloxacillin. The described composites are highly specific for the analysed model Escherichia coli strains and may be used in the future as new substitutes for commonly used antibiotics in clinical and nosocomial infections in the progressing pandemic era. The results show much stronger antibacterial properties of the functionalised membranes on the action of bacterial membranes in comparison to the antibiotics in the Fpg digestion experiment. This is most likely due to the strong induction of oxidative stress in the cell through the breakdown of the analysed bacterial DNA. We have also observed that the intermolecular distances between the functional units play an important role for the antimicrobial properties of the used material. Hence, we utilised the idea of the 2D solvent to tailor them.     

Transition between two solid-solutions: Effective and easy way for fine Ce1−xGdxO2−x/2 powders preparation

Ceria, pure or doped, is an important electrolyte material in solid oxide fuel cells, catalysts, and plutonium surrogates. Even though ceria is a widely studied material, its coprecipitation with the most common doping element, gadolinium, remains mostly overlooked. Here, we present a comprehensive study of gadolinium–cerium oxalates prepared by coprecipitation of gadolinium (III) and cerium (III) salts by oxalic acid under different reaction conditions and element ratios. For this purpose, we assessed the effects of basic precipitation conditions on the final oxalate size, shape, and conversion into the corresponding oxides. The results showed that coprecipitation with oxalic acid yields and ideal solid solution, which translates into the oxides. This low-cost and straightforward synthetic route provides then high-quality solid solutions of Ge–Gd in the oxide lattice. Thus, this approach has a high industrialization potential, with significant advantages over hydrolysis or hydrothermal techniques.     

The impact of glycated pea proteins on bacterial adhesion

Adhesion is one of the bacterial strategies indispensable for colonization of the small intestine. Food components reaching the small intestine, are not only digested and absorbed there, but may also influence the microorganisms colonizing the mentioned region. In this way, nutrients, particularly the ones the enzymatic degradation of which is hindered, acquire the ability to modify the adhesive potential of the autochthonic microorganisms. The glycated food proteins are noteworthy here for they often undergo relevant structural and functional alterations. Such proteins tend to display a lowered susceptibility to enzymatic degradation and thus may act as modulators of both metabolic activity and adhesive potential of bacteria adhered to the intestinal cells. For that reason, this study aimed at establishing the impact of the glycated pea proteins on adhesion of the bacteria from the genera: Lactobacillus, Enterococcus, and Escherichia, which are typical for the human small intestine.     

Study on the new bone cement based on calcium sulfate and Mg,CO3 doped hydroxyapatite

In order to improve some features of bone substitutes the new self-setting composite-type implant material based on Mg²⁺/CO₃^2? co-substituted hydroxyapatite (Mg-CHA) and calcium sulfate hemihydrate (CSH) was developed. Synthetic hydroxyapatites doped with small amounts of additives found in natural bone (e.g. Mg²⁺ and CO₃^2?) are regarded as promising components of calcium phosphate bone cements (CPCs). The CPCs, now available on the market, due to low resorption rate are too stable to permit material degradation and are slowly replaced by the newly formed bone. To improve cement resorption we used calcium sulfate which is a well-known biodegradable and biocompatible bone defect filler. Combining properties of Mg-CHA and CSH allowed developing a new, promising, easy shapeable implant material with high potential for bone regeneration.